A natural elevation of the earth's surface having considerable mass, generally steep sides, and a height greater than that of a hill, Something resembling a mountain in being large; something of extraordinary magnitude; a great heap_ as, a mountain of rubbish, A range, chain, or group of such elevations, adjective_ Of or pertaining to a mountain or mountains; growing or living on a mountain; found on or peculiar to mountains; among mountains, a portable barometer, adapted for safe transportation, used in measuring the heights of mountains,